Plunger-supporting plug for sprayers



June 22, 1948. c ARMSTRONG 2,444,015

PLUNGER-S UPPORTING PLUG FOR SPRAYERS f Filed Oct. 16, 19 46 INV ENT OR.

Patented June 22, 1948 PLUNGER-SUPPORTING PLUG FOR SPRAYERS Jurl 0.Armstrong, Grand Rapids, Mich., assignor to Universal Metal ProductsCompany, Saranac, Mich., a corporation of Michigan Application October16, 1946, Serial No. 703,630

6 Claims.

This invention relates to insect sprayers and the like and moreparticularly to the plugs or plunger rod supports mounted in the rearends of the tubular barrels of such sprayers.

Sprayers of the type to which this invention is applicable ordinarilyhave a tubular barrel attached at its front end to a small can or glassjar containing the powder or liquid to be sprayed out. Inside the barrelthere is a plunger mounted on the inner end of a rod that projects fromthe rear end of the barrel where it carries a handle by which theplunger can be reciprocated to force jets of air out of a small openingin the front end of the barrel. To support the plunger rodconcentrically with the barrel and to prevent the plunger from beingpulled out of it, a plug is mounted in the rear end of the barrel and isprovided with a central passage through which the rod slidably extends.In the past, most of these plugs have been wooden cylinders held in thebarrels by screws or by portions of the barrels bent into depressions inthe sides of the plugs. Some attempts have been made to use othermaterials and other types of rod supports, but generally they have notbeen very satisfactory. One difficulty has been the increased cost ofsuch substitutes. Where metal supports have been provided it has beenfound that when a plunger rod is reciprocated in a barrel it slidesagainst the support and causes the metal to vibrate and produce anundesirable and irritating squeak.

It is among the objects of this invention to provide a plunger rodsupport which is made of metal which is easy and inexpensive'to make andto assemble with a sprayer barrel, which is strong and rigid, and whichdoes not produce a squeak when the plunger rod is operated.

In accordance with this invention a piece of thin sheet metal is formedinto a short cylindrical body of a size that will fit snugly in thetubular barrel of a sprayer. One end of the body preferably is turned into form a strengthening radial flange. A portion of the body near itsopposite end is bent radially inwardly to form a depression in its outersurface and a projection inside the body. This can be done convenientlyby pressing inwardly an annular section of the body to form an annulargroove which in turn produces an annular bead inside the body. A rigiddisc, preferably made of relatively thick metal is disposed in theunflanged end of the bodi and clamped against the internal bead by meansof the adjoining edge of the body which is bent inwardly over the edgeof the disc. When the plug is inserted in the rear end of a sprayerbarrel the end of the barrel isrol'led into the annular groove in theplug to lock the two members together. The outside diameter of the plugat its outer end preferably is slightly larger than the inside diameterof the barrel to limit the distance the plug can be inserted in thebarrel. The center of the plug disc is provided with an opening in whicha plunger rod slides but the stiffness of the disc keeps it fromsqueaking.

The preferred embodiment of this invention is illustrated in theaccompanying drawings in which Fig. 1 is a side view of a typicalsprayer with parts of the barrel broken away; Fig. 2 is an enlargedfragmentary longitudinal section through the plug and rear end of thebarrel; Fig.

3 is a view of the outer end of the plug alone;

and Fig. 4 is a side view of the two elements of the plug before theyare assembled.

Referring to Fig. 1 of the drawings a tubular sheet metal barrel l isdisposed tangentially of a cylindrical metal can 2 provided with aremovable screw cap 3 by which the can may be filled with an insecticideor the like. The front end of the barrel is soldered to the can and isprovided with a small central air outlet 4. A small tube 6 extendin downinto the can, has its upper end located directly in line with the lowerportion of this outlet so that air blown across the tube will Withdrawthe contents of the can as a mist in a well-known manner.

Disposed inside of the barrel is the usual leather piston or plunger 1to the center of which is secured a rod 8 that extends back through thecenter of the barrel and out of its rear end. Mounted on the outer endof the rod is a hand-1e 9 so that the plunger can be reciprocated in thebarrel to force jets of air out through the hole 4 in its front end. Toslidably support the rod axially of the barrel and to limit the distancethat it can be withdrawn a supporting member in the form of a hollowplug is rigidly mounted in the rear end of the barrel.

It is a feature of this invention that the plug can be made entirely ofmetal, preferably from only two parts, permanently joined together.Accordingly, the larger part or body I l, which forms the side Wall ofthe plug, is made from a single piece of light gauge sheet metal, suchas tin plate, that has been formed into a short cylinder having adiameter that causes it to fit snugly in the sprayer barrel. One end ofthis cylinder maybe enlarged slightly (Fig. 4) so that it will strikeagainst the rear end of the barrel to limit the distame the completedplug can be inserted in the barrel. As shown in Fig. 2, it is quitedesirable to turn the opposite or inner end portion of this cylindricalbody inwar ly in order to form a strengthening flange l2 that willinsure that the body will remain Cylindrical during the succeedingoperations. The width of this flange need not be great, and for bestresults should not be great enough to engage the plunger rod, A shortdistance from the outer end of the body; that is, at the inner end ofthe enlarged portion, an annular section is bent radially inwardly, suchas by rolling, to form a groove I? that encircles the body.

The body of metal displaced inwardly by this groove forms a circularbead it inside the body shown in Fig. 4.

The other part or end wallof the plug consists of a disc l5, mostsuitably of metal, which is inserted in the outer end of the cylindricalbody 1 l I in engagement with the internal bead it where it joins. theenlarged end of the body. The enlarged outer end of the body is rolledor crimped inwardlyover-the edgeof the disc, as at ll, to clamp itagainst the bead and thereby lock the two parts of the plug tightlytogether. The center of the disc is provided with a hole 58 throughwhich plunger rod 8 slides. In order to avoid squeaking when the rod ismoved back and forth through the disc, the disc should be stiff enoughto prevent it from vibrating. disc preferably is made ofniaterial, suchas l9. or 20 gauge iron,,much thicker than the wall of the plug body.The dis-c is strengthened further by making it convex.

The plug is inserted in therear end of. thesprayer barrel until theenlarged outer end of the plug behind groove I3 strikes against thebarrel.

disc. However, if for any reasonit is desired-to wait until after thedisc has-been mountedin the body-before forming groove l3, the-shoulderconnecting the enlargedouter end of the body to the rest of it willsupport oneside of the disc while the outer endof the body is bent over.the edge of the opposite side. This shoulder becomes part of theinternal bead when the circular groove is formed in the body.

A plunger rod support made in accordance. with this invention costs nomore, or even costsless, than wooden, plugs used heretofore for the samepurpose. This metal plug has the advantagethat it can be madeconveniently in the same metal working shop; in which the rest of thesprayer is; manufactured. It-alsouis .a satisfactory subs-tie:

tute for wooden plugswhen wood. is scarce.

According. to the provisions of the patent statutes, I have explainedthe principle. and construction of my invention and have illustrated anddescribed-what I now consider to represent its best embodiment. However,I desire to have it understood that, within the. scope of the appendedclaims, the invention may be practiced otherwise than as specificallyillustrated and de scribed. i

I claim:

l. Thecombination with a tubular barrelhavingan annular bead formed: inits rear end, a

plunger in the barrel, and a plunger rod connected Accordingly, the

to the plunger and extending out of the rear end of the barrel forreciprocating the plunger, of a plunger rod support comprising acylindrical sheet metal body fitting snugly in the rear end of 6 saidbarrel, the inner end of said body having an inturned flange, an annularsection of said body neari s nte lendbe e b n radial y i wa y form anannular groovereceiving said bead to hold said body in the barrel, and ametal disc disposed in the outer end of said body, the outer end of thebody being bent inwardly over the edge of the} disc to holdit in place,and the center of the disc being provided with an opening through hi h sid od Slidellly eXtends.

mbjpa on with a tubular barrel havnuanlbead formed in its rear end, aplungergn thebarrel, and a plunger rod connected' tothe plunger andextending out of the rea'r end of the barrel for reciprocating theplunger, of a plunger rod support comprising a cylindricalsheet. metalbodyfitting snugly inthe a e d. o ta d b r e inne d o ai v body havingan inturned flange, an annular sec: tion of saidbody near its .outerendbeing bent d allyi Wa d -tof rm an ann r ew-e r ceiving said, beadtoholdsaidbody in the barrel, and aconvex metal discdisposed in; the .outer;endoisaidbody, the outer end of thebody being bent inwardly ,over theedge ofthe disc to holdit pleee and t center f. t d sc. b ing oded; withan. o e ing th o h hi sgi fab r exte ds 'rhe c mb nati n ha ubula -barrl av i a nnulanb edi formed it r ar nda p un in th ba rel r d a unee iodli QCG to the plu er-and ext ndi g out. o h rear. endnof the barrel 9...reciprocating thei un e f f e p mseL -su o t om risin a cyl ndric l:h tm t ody fi i es uelyin; h anend. ofa eid, ee v he, nne n i ody-h vinterned ang a nu a tion of said body near its outer. end being bent ada l inwa ly t ormer n ular-steam r Q i e-Sa d; he d hol a d b drt b r i,a -a me aldi cot ma rially e ter hick-1 ness. than the wall,ofthgbodydiispbsed irrthe uter d: Dream-bode the te p he qdr ing ennwardl o er. he ee ie ies to ol i in: P ce dt e nter, t dis beingrovided wi h n en hrou h- Which d, rod 1 .blvie te dsih qmbinatiqn it aubu a i a re 1 th" ing an. annula-r befi .formedin itsrear, end,.-a pluner in the-,ba r Land PI n rI e etted to t eip neernd e t n n ou f. t e.e r .end, o the. bar el or r c prpc tins h p un er. o a ucgen ods ppqrtcmer- -s naa cyl ndrical- 'l fit/ met r ki l fi t n snu ly i in the eaen o sa d ba r l. tbeinner e dc ,seid'b r; aving enintirn dflanee an nnua S ti n: O a isiib drineerflit ho ter end being bent ad nt n ardly, to,form an ann l r; e oere. recei i aid besdt .hold aid bod in e ba themaximum.di meter-s -wid bo y b tw ents outer nd an s idg c ebems r ateran the. ma mundiemeter oitherestb the bcdytp li it the. st nce he body.can. be -.ins.e ted..i. the, banetand a me l. d Q;.d p/Q Q. mem e e dbfsaid bod the ,0 tencnd Qtt bns rb ine.

. bentinwardly overt... dge oithesi sc, tecllamp.

it, against ai nest o tt el bQdy. amitba snt r,

in the barrel, and a plunger rod connected to the plunger and extendingout of the rear end of the barrel for reciprocating the barrel, of aplunger rod support comprising a cylindrical sheet metal body fittingsnugly in the rear end of said barrel and being bent radially inwardlynear its outer end to form a depression in its outer surface forreceiving said projection to hold said body in the barrel, and a rigiddisc disposed in the outer end of said body, the outer end of the bodybeing bent inwardly over the edge of the disc to clamp it in place, andthe center of the disc being provided with an opening through which saidrod slidably extends.

6. The combination with a tubular barrel having an internal annular beadformed in its rear end, a plunger in the barrel, and a plunger rodconnected to the plunger and extending out of the rear end of the barrelfor reciprocating the plunger, of a hollow metal plug mounted in therear end of the barrel and provided with a passage through which saidrod slidably extends, said plug consisting of a cylindrical sheet metalbody fitting snugly in said barrel and having an inturned flange at itsinner end, the outer end of said body projecting from the barrel a shortdistance, an annular section of the body just inside the barrel beingbent radially inwardly to form an annular groove in the outer surface ofthe body and an annular bead on its inner surface, said barrel beadbeing seated in said groove to lock the barrel and plug body together,and a convex metal disc disposed in the outer end of said body andprovided with a central opening through which said rod extends, theouter end of said body being bent inwardly over the edge of said disc toclamp it against said body bead, and said disc being rigid andrelatively thick to avoid squeaking as the plunger rod slides throughit.

JURL C. ARMSTRONG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 632,801 Brooks Sept. 12, 1899715,982 Chapin Dec. 16, 1902

